1. Field of the Invention
The present invention relates generally to a method of connecting cylindrical members to each other. More particularly, the present invention relates to a method of connecting cylindrical members such as pipes, cylindrical casing segments or the like to each other using a tandem type internal clamp.
2. Description of the Related Art
Before cylindrical members, e.g., pipes each having a comparative large diameter are connected to each other by employing a welding process, many manhours are required for achieving preliminary works which are exemplified by a pipe laying operation, a centering operation, a welding groove aligning operation, and an adjusting operation.
Especially, when a centering operation and a welding groove aligning operation are performed in a working site, it is necessary to conduct two preliminary works in order to hold pipes in the correct positional relationship in such a manner as to allow the end face of one pipe to be correctly aligned with the end face of other pipe to be connected to the one pipe. One of the preliminary works is such that a metallic member that is called a temporary lug is provisionally welded to the peripheral surface of one pipe at the position in the vicinity of the end face of the latter, and the other preliminary work is such that a wedge-shaped member that is called a bat is squeezed below the temporary lug by actuating a hammer or the like tool.
In addition, when a pipe connecting operation is practically performed at a high working site, e.g., a pipe rack or it is performed in a narrow space such as a pipe trench, a culvert or the like, it is completed only with much difficulties. In the circumstances, many requests have been hitherto raised from welding operators for providing a method of connecting cylindrical members such as pipes, cylindrical casing segments or the like to each other with a higher level of safety.